1. Field of The Invention
The present invention relates to an improved, topically applied base composition providing enhanced conditioning for personal care compositions. In particular, it relates to a non-occlusive moisturizing base for imparting extended skin care properties to conditioning gels, lotions, cremes, sticks, splashes and sprays.
2. Description of The Prior Art
It has long been desired to provide body conditioning and refreshment without the heavy, greasy and occlusive characteristics of vaseline-mineral oil- and lanolin-based compositions. Skin and scalp conditioning is recognized as a necessary adjunct to reduce or prevent harmful drying effects to the skin and hair caused by use of detergents, toilet bar soaps, shampoos, antiperspirants and the like. It is also well understood that the drying and cracking effects on the skin caused by extended exposure to the sun and low humidity requires an effective conditioner and moisturizer to return cutaneous tissue to its normal softness and moisture levels.
It is now understood that from a biochemical standpoint, dryness is, in part, a measure of the water content of the skin. The skin becomes dry because of excessive loss of water from its surface and the subsequent loss of water from the stratum corneum. Continuous and prolonged immersion in various soaps and detergents, use of shampoos and antiperspirants and exposure to the sun or infrared and/or ultraviolet radiation all contribute to drying the stratum corneum. Surfactant based cleansers including soaps and shampoos promote dissolution of skin surface lipids, horny layer lipids and hydroscopic water-soluble components in the corneum. This, in turn, leads to the development of so called "dry skin" with concomitant cracking, flaking and scaling of dead corneocytes.
It has long been a desideratum of the personal care industry to find a non-oily, water-soluble base composition which would permit satisfactory removal of excess surface oil, soil and skin debris, but would allow recovery of normal oil levels, thus protecting the skin surface from drying out and from losing needed moisture to permit it to maintain an attractive appearance. Such a vehicle or base, when employed in the full spectrum of skin and hair care products, would assist in maintaining oil content, reducing scaling and increasing removal of preexisting scale. When employed in after-bath and shower body splashes, it would refresh and condition the skin while providing extended protection against drying out.
Various synthetic and natural emollients have been proposed to allow recovery of normal oil levels, when used in combination with or after use of, detergents, soaps or other surfactants. However, none have been entirely satisfactory.
Measurement of "conditioning" effects has proven elusive and uncertain as illustrated in Pavlichko, et al., COSMETIC TECHNOLOGY, pp. 40-42, June 1981. One accepted measure of emolliency is made with a sebumeter which quantifies levels of surface oil on the skin. Another useful measurement of emollience is made by tape-stripping treated skin to remove dead corneocytes from its surface to indicate the degree of dryness of the skin. Slides of treated skin taken with a scanning electron microscope illustrate whether or not a protective film is formed over the skin and the nature of such a film.
Typical cosmetic formulations to help prevent formation of dry, scaling skin are disclosed in U.S. Pat. Nos. 4,268,502, 4,268,526 and 4,272,544. These patents disclose cleansers, tonics, cremes and lotions containing certain of the key ingredients of the present invention, but not the vehicle or base composition which is an important part of the present invention.